Apparatus for forming dental plates



(No Model.) 2 Sheets-Sheet l.

W. W. EVANS.

APPARATUS FOR FORMING DENTAL PLATES.

No. 279,365. I Patented June 12,1883.

WITNESSES IJVVENTOR (No Model.) 2 Sheets-Sheet 2. W. W. EVANS.

APPARATUS FOR FORMING DENTAL PLATES.

Patented June 12,1883.

W! IIWESSES UNITED STATES PATENT OFFICE.

W. WVARRINGTON EVANS, OF \VASHINGTON, INSTRIOT OF COLUMBIA.

APPARATUS FORFORMING DENTAL PLATES.

SPEGIFICATION forming part of Letters Patent No. 279,365, dated June 12, 1883.

Application filed November I, 1882. No model.

T0 on whom it may concern:

Beit known that I, W. VVABRINGTON Evans, a citizen of the United States, and residing in the city of Washington, in the District of Columbia, have invented certain new and use ful Improvements in Apparatus for Forming Dental Plates, of which the following is a specification.

The invention relates specially-to a dental 1o vulcanizer in which the flasks are placed within a chamber or vessel having a surrounding inclosed water and steam space; and my improvements relate to means whereby the said chamber or vessel may be the more perfectly cast or constructed, so as to insure greater safety in its use.

The invention further relates to a construction whereby, in drawing the flasks together, no strain is placed upon the boiler to weaken or have the tendency to fracture it.

0 paratns, as particularly hereinafter explained.

In the accompanying drawings, Figure 1 is a side elevation of the apparatus. Fig. 2 is a vertical section. Fig. 3 is a plan view. Figs. 4, 5, 6, and7 are details.

Similar letters of reference indicate similar parts in the respective figures.

A is the outside case, made of malleable iron or other metal'which is not a ready conduotor of heat. It may be constructed as .0 shownthat is, as a hollou shell in the form of a frustum of a coneor of other suitable shape.

B is a lamp, and a are apertures cut in the sides of the case to insure the necessary admission of air to supply the flame.

O is the boiler, which is made in two cups, b and c, the space d between the two forming a water and steam chamber. The outer cup, I), is provided at its top with an internal thread,

' b, andthe inner cup,.c, with athreaded flange,

c, by means of which the two cups are united.

By making the boiler in two parts complication in casting is avoided, and both sections may be examined before being fitted together, thereby rendering it certain that sound castings are employed, which aids greatly in insuring safety in the use of the apparatus. The boiler may, however, be made in one casting. The lower part of the space (I, or that over the lamp, is contracted in width to decrease the body of water at that point and facilitate the action of the flame on the fluid.

D is the cap, having lugs 0,.w11ich, on the cap being turned, fit over the inclined planes 6 at the top edge of the boiler, securing the cap in place. 1 The cap is provided with annular re cesseSf, which fit over corresponding projections, f, formed on the top face of the flange 0, close joints being obtained by the use of any suitable packing material. The cap has three or more holes in its top, through which pass the bolts g,'which are employed in drawing the flasks E together. As shown in Fig.

.2, the bolts are provided with spherical heads 9, which rest in washers 9, made of lead or other suitable material, resting within recesses formed in the cap D, the lower ends of the bolts tapping into aplate, 71, upon which plate the fla'sks' rest; The under side of the cap is provided with projections 2',

which rest upon the top of the upper flask.

As the bolts are turned by the use of a wrench on their upper square ends, it will be seen that the plate 71. is raised or lowered as the bolts are turned to the right or left. As

the plate 71 is drawn up the flasks are crowded against the projections i on the under side of the cap, and no strainwhatever is plaeedupon the boiler.

In order to allow for any slight movement of the bolts 9 at their upper ends,

consequent upon irregularities inthe flasks, or

other cause, thebolt-holes in the flask are enlarged or widened top and bottom, which allows the bolts to move upon their spherical heads after the manner of the well-known universal joint formed by a ball and socket. In Fig. 4 a modification of the bolt and plate h is shown, the lower end of the bolt having a countersunk head fitted in the plate in which it revolves, the upper end of the bolt being threaded and working in the cap D as a nut. The bolt is provided with a conical washer or Ibo ring, j which seats upon a lead washer inserted in the cap. A small pin, 7c, may be driven through the top end of the bolt across the conical ring j. The center of the cap D is perforated for the insertion of a thermometer, Z, to indicate thetemperature of the vulcanizing or dry chamber. A lead washer, Z, is inserted at the joint. If desired, the thermometer may be withdrawn and a central plunger for pressing on the top of the upper flask be inserted, or a handle for removing the lid be used.

In Fig. 5 is shown a safety-valve for attachment to the boiler, the boiler being shown in this figure as cast in one piece. Ascrew-plug, m, is tapped into the solid part c at the top of the space (1. "Within the plug is a tensionscrew, on, having a longitudinal steam-opening, m. At the inner end of the screw mis a spring, or, against which bears the back of a conical. valve, 02, its stem at entering the spring. The conical valve seats in the solid part c", a minute aperture, 0, leading from its point into the steam-space of the boiler. An overpressure of steam will be relieved through the opening 911. As shown in Fig. 6, the safety-valve is applied to a boiler made in two parts.

In order to allow steam or vapor to escape from the dry chamber after the vulcanization has been completed, I provide a small screwvalve, which, on being turned in theproper direction, opens communication from the drychamber to the outer air. Steam maybe admitted to the dry or vuleani'zingv chamber by means ofa screw-valve, q.

As shown in Fig. 7, a'thermometer is screwed into the plug 0, which plug is hollow,com municating with the steam-chamber, and may be provided with a spring relief-valve, I, having atensioirscrew, t, by means of which valve an overpressure of steam may be prevented, instead of by the special relief-valve shown in Figs. 5 and 6. If desired, a steam-gage may be substituted for the thermometer.

\Vatcr may be admitted to the boiler on unscrewing the packing-nut 0', into which the thermometer is screwed.

A hinged door, 8, is placed at the bottom of the casing, and provided with an isinglass panel, through which the flame may be viewed. The hinged door admits'of the ready introduction and removal of the lamp or gas-burner.

The cups forming the boiler may, instead of being cast, be spun or beaten to shape.

The improvements in construction constituting my invention are such as will be readily understood and appreciated by manufacturers and users of this class of apparatuses.

I disclaim in general terms the suspending of the flasks within the boiler, as also the use of a safety-valve as an adjunct to the boiler. I also disclaim the combination of 'a boiler, a cover having stuffing boxes, rods, platen, cross-bar, and a central screw, whereby the flasks on the platen may be drawn up against the under side of the cover but I claim as my invention 1. A boiler for a dental vulcanizer, constructed in two separable parts, forming a continuous and surrounding inclosed water and steam chamber, as contradistinguished from aboiler made in one homogeneous body, as set forth.

2. A boiler for a dental vulcanizer, co1nposed of two separable cups united concentrically to form a water and steam space, sub stantially as set forth.

3. The combination of a boiler, a cap, a sup porting plate or platen for the flasks, and

screw-bolts for drawing said platen against the cap, whereby no strain is placed upon the boiler, substantially as set forth.

4:. A boiler and a platen combined with a cap having reversely-inclined bolt-holes, and suitable packingwvashers, and screwbolts having spherical heads, substantially as set forth.

5. Ina dental vulcanizer, a boiler having circumferential inclined planes and annular projections upon its upper face, combined with a cap having securing-lugs and annular dcpressions upon its under side, substantially as set forth. 7 A I 6. The combination of a platen, a cap, and a screw-bolt, the latter having a head counter sunk in the under side of the platen, and its upper part tapped into the cap, and provided with a conical ring and securingpin, substantially as set forth.

7. The combination, with a boiler fora dental vulcanizer, of a screw-plug longitudinally perf rated, and exteriOrly-adjustable tensionscrew, helical spring, and conical valve, backseating against said spring, the apex of the valve seating against a minute aperture lead ing to the steam-space in the boiler, substantially as set forth.

8. The combination, with the casing of a dental vulcanizer, of a hinged door having a transparent panel, substantially as set forth.

In testimony whereof I have hereunto set my hand and affixed my seal this 26th day of October, 1882.

W. WARRINGTON EVANS. [1,. Vitnesses:

GEORGE H. HOWARD, G. B. HARRIs. 

